1. Field of the Invention
The present invention relates, in general, to devices for raising and lowering light fixtures, and in particular, to an electrically motorized apparatus to raise and lower chandelier light fixtures to facilitate cleaning and changing of bulbs.
2. Information Disclosure Statement
A preliminary patentability search in class 362, subclasses 147, 384, 404, 391, 418, and 403, produced the following patents, some of which may be relevant to the present invention: Farrington et al., U.S. Pat. No. 2,609,170, issued Sept. 2, 1952; Pfaff, U.S. Pat. No. 3,610,584, issued Oct. 5, 1971; Booty et al., U.S. Pat. No. 4,316,238, issued Feb. 16, 1982; and Sakurai, U.S. Pat. No. 4,381,539, issued Apr. 26, 1983. Additionally, during prosecution of the predecessor of this application, an advertisement of a floodlight lowering attachment, dated Mar. 11, 1938, manufactured and sold by the Benjamin Company under the name "SAFLOX", was cited by the Examiner. While each of the above references disclose various apparatus for raising and lowering light fixtures, none disclose or suggest the present invention. More specifically, none of the above patents disclose or suggest a motorized light fixture lift system, comprising: a hoist mechanism for raising and lowering a light fixture between a raised position adjacent a ceiling and a lowered position distant from the ceiling, said hoist mechanism comprising: a drive motor including a drive shaft, and a take-up shaft coupled to the drive shaft; a ceiling junction box including a first set of contacts for supplying a source of electrical power to the light fixture; a canopy junction box attached to the light fixture comprising a second set of contacts mounted for receipt of electricity from the first set of contacts when the light fixture is in the raised position; and, a single hoist cable attached at one end to the take-up shaft for being wound upon said take-up shaft and attached at the other end to the canopy junction box.
Farrington et al., U.S. Pat. No. 2,609,170, describes a motor driven lamp hanger with multiple embodiments. The Farrington device, as described, has four cables supporting the lamp fixture which are wound on four separate drums. The Farrington patent also describes upper and lower limit switches to shut off the power to the drive motor at the extremes of travel of the lamp fixture, as well as fixed and mating contacts to supply power to the lamp fixture when in the raised position. The present invention has only a single cable supporting the light fixture, not a multiplicity as in the Farrington device.
Pfaff, U.S. Pat. No. 3,610,584, describes a lowering mechanism for a light fixture which comprises a drive motor and braking mechanism, said drive motor being coupled through a chain drive mechanism to a take-up shaft comprising a pair of drums, each of which winds a flexible ribbon or tape which is attached to the light fixture. The present invention has only a single cable supporting the light fixture, not a multiplicity of ribbons or tapes as in the Pfaff device, and uses no chain drive mechanism to couple the take-up shaft to the drive motor.
Booty et al., U.S. Pat. No. 4,316,238, describes a light fixture and elevator therefor, comprising a horizontally reciprocal carriage, a biasing spring attached to the carriage, said carriage moving horizontally as the light fixture is raised and lowered. A hydraulic piston may be attached to the carriage of the Booty device for controlling the rate of movement of the carriage, and therefore the descent rate of the light fixture. Unlike the present invention, the Booty device is manually operated and is not motorized, and has no contacts which interrupt the flow of electricity to the light fixture when the light fixture is not in the raised position. Also, the present invention has no such horizontally reciprocal carriage or biasing spring.
Sakurai, U.S. Pat. No. 4,381,539, describes a non-motorized height level adjusting means for a light fixture comprising a string winder with ratchets which wind a plural number of strings or wires, attached to the light fixture, onto a plural number of spools. Unlike the Sakurai patent, which is manually operated, the present invention is motorized and has only a single hoist cable attached to the light fixture. Also, the Sakurai patent, like the Booty device, has no contacts which interrupt the flow of electricity to the light fixture when the light fixture is not in the raised position.
The advertisement for the Benjamin "SAFLOX" floodlight lowering attachment shows a hand operated mechanism that raises and lowers an outdoor floodlight. The mechanism includes two sets of contacts that meet and are protected when the lamp is in the raised position, but is not motorized as is the present invention.